Indemnification Asset - Summary of Activity in Balance of Indemnification Asset (Liability) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
FDIC Indemnification Asset [Roll Forward]
Beginning balance	$ (521)	$ (349)	$ 206
Effect of actual covered losses (recoveries) and increase (decrease) in estimated future covered losses	(412)	(93)	(853)
Change in estimated "true up" liability	(86)	(71)	(100)
Reimbursable (revenue) expenses, net	2	4	85
Payments made (received)	273	(12)	313
Ending balance	(744)	(521)	(349)
Amount of indemnification asset (liability) recorded in other assets	(60)	77	(349)
Amount of indemnification liability recorded in other liabilities	(684)	(598)
Ending balance	$ (521)	$ (349)	$ 206